Nozzle assemblies in hot runner systems are generally known in the art. In these existing systems, the gate nozzle assemblies are mostly fixed to the nozzle body of the gate nozzle assemblies. During a drastic change in the temperature of the hot runner system after the introduction of the molten plastic, the nozzle body expands predominantly in a longitudinal direction thereby relocating the gate nozzle assemblies along the longitudinal axis. Therefore, a need exists in the hot runner industry for a better method of assembly and installation of edge gate systems for such molding process, where such methods need to counter relocation of the gate nozzle assemblies, which might cause misalignment of corresponding components during the molding process.
Since, the edge gate systems typically need to be side loaded into the mold cavity, and then slid in to the gate seal where some clearance is required between the gate seal and the manifold to allow the molding procedure to be initiated. Therefore, when the assembled hot runner system is installed into the molding machine and injected with the molten plastic, the clearance between the gate seal and the manifold is a section that can leak plastic, thereby causing failures with the hot runner assembly. It is essential this seal area can withstand the injection pressure of the melt stream passing through it. Prior art devices addresses this potential leaking situation by using Belleville style washers. The gate assembly with this type of washer, when not installed into the mold/hot runner system, is larger than the area in which it will be installed into. When the gate assembly is inserted into the mold cavity and then the hot runner, this Belleville washer acts like a spring, compressing and applying a preload between the face of the gate seal and the hot runner
The use of Belleville washer has several technical limitations such as a very low amount of force that is generated and the reduction in spring force that occurs because of heating and cooling cycles of the washer, as the hot runner system is heated and cooled. This results in the spring force of the Belleville washer being reduced over time to the point that it cannot withstand the force generated by the projected surface of the material flow path within the hot runner and gate seal. This results in leaking past the seals and thereby rendering the hot runner system unusable. There is a need for a device that addresses the problems noted above and employs the use of a convenient material for the construction of the sealing members in the overall assembly.